As open as he is to a plurality of materials, Adjaye has a fixed take on the dichotomy between public and private structureswhich is another reason his work seems so stylistically varied. His public buildings, especially his libraries, welcome outside interaction. Adjaye has spoken in the past of markets and public squares in Africa in which it’s unclear where the commuting ends and the commerce begins. The thresholds between his buildings and their environs are similarly blurred. His design for the Moscow School of Management merges its classrooms, plazas and residences on one huge, elevated circular base. He’s fond of strategies that allow passersby to get a glimpse inside, as with the dark gray glass that veils the Museum of Contemporary Art in Denver and the cheerful colored glass of his Idea Store in London. Sometimes he puts buildings within buildings, creating a space that’s neither outside nor inside.

By contrast, the residences Adjaye has designedfor clients including Ofili, Ewan McGregor and his wife Eve, the artist couple Sue Webster and Tim Noble, and the late Alexander McQueenoften seem from the outside to be hermetically sealed. The exterior of Webster and Noble’s East London home, known as the Dirty House, is completely black, with mirrored windows on the ground floor set flush to the wall. It’s essentially a two-story invitation to go away. “When the Dirty House was first completed, everyone who thought they knew you and what you stood for was in a state of shock,” Webster says. “It was like a spaceship had landed in Shoreditch, and London had never seen anything like it.”

The home Adjaye designed for art collectors Adam Lindemann and Amalia Dayan is even more conspiratorial. It’s hidden a few feet behind the front wall of a landmarked New York City carriage house linked to only one window via a glass bridge on an upper floor. The austereor falsefacades of Adjaye’s private homes often open up to completely glassed walls at the back, or the homes have panels of translucent glass or multiple, eccentrically shaped skylights that allow in outside light but not sight. (The McGregors’ house features an all-glass, fishbowl-like dining area jutting out into their walled back garden.) The effect is privacy and sanctuary, but with surprises.

One of Adjaye’s first jobs as a young designer was in the studio of ultraminimalist architect David Chipperfield. Despite Adjaye’s stated allergy to the confines of style, his structures serve up similarly clean edges and crisp forms. Their geometry is rarely complex, their facades rarely sculpted. Unlike classic minimalists, however, Adjaye believes in decoration. The management school he designed in Russia has aluminum and glass curtain walls as flat and hard as ice cubes, but the surface is a riot of chevron shapes and color. Even the stark black street fronts of his residential work are decoration of a type; they were painted that color for no reason other than to catch the eye.

Ed Reeve—Adjaye Associates

For the NMAAHC, Adjaye has taken his deco-minimalism to a new level. The exterior of the building will be clad in aluminum panels Adjaye has developed. Inspired by the mastery of pre–Civil War African-American guilds in the South, he made a cast of wrought iron he saw in Charleston, S.C., abstracted it and created a new pattern. These bronzed aluminum panels will form a lattice that wraps around the museum, merging the exterior and the interior as well as the old with the new.

“I didn’t want just another marble building on the mall,” says NMAAHC director Lonnie Bunch. “The bronze color spoke to me of a permanent dark presence that’s always been in America.” Bunch, who told Adjaye about the guilds, has been impressed with his architect’s voracious curiosity. Adjaye has immersed himself in the history of the slave trade, which he calls “the first globalization” and compares to the mortgage-securities industry in its complexity.

The Smithsonian is something of a homecoming for Adjaye. He has long been a champion of African architecturenot of the edifices of colonialism with their air of permanence but of the construction that takes place where labor is plentiful and materials and machinery are not. Over the course of 10 years, he visited every African capital to document such infrastructure. “I can look at a slum dwelling purely as a visual thing,” he says. “The question is, If you only had these elements, what did you make? And is that interesting or not?”

While it’s too simplistic to say Adjaye’s designs are African, there’s something southern hemispheric about his eclectic use of materials, decoration and structure. It’s less perfect and more resourcefulmore particular to the humans who will use it and adapt itthan much Western architecture. Adjaye’s style may be slippery, but his approach is not. “For me, the business of being an architect is not about perfecting one’s style,” he says, “but about a very profound engagement with society.”

For his sometime collaborator, the Danish-Icelandic sculptor Olafur Eliasson, the trademark of Adjaye’s work is that it transcends trademarks. “David managed to develop a signature which is not just about style,” he says. “Human nature is his inspiration.”